As is generally known, surgical drapes have been designed to greatly reduce, if not prevent, the transmission of liquids through the surgical drape. In surgical procedure environments, such liquid sources include patient liquids such as blood, saliva and perspiration, and life support liquids such as plasma and saline.
Many surgical drapes were originally made of cotton or linen. Such surgical drapes fashioned from these materials, however, permitted transmission or "strike-through" of various liquids encountered in surgical procedures. In these instances, a path was established for transmission of biological contaminates, either present in the liquid or subsequently contacting the liquid, through the surgical drape. Additionally, in many instances, surgical drapes fashioned from cotton or linen provided insufficient barrier protection from the transmission therethrough of airborne contaminates. Furthermore, these articles were costly, and of course laundering and sterilization procedures were required before reuse.
Disposable surgical drapes have largely replaced linen surgical drapes. Advances in such disposable surgical drapes include the formation of such articles from liquid absorbent fabrics and/or liquid impervious films which prevent liquid strike-through. For example, see JP 8080318 assigned to Kyowa Hakko Kogyo K K; U.S. Pat. No. 5,546,960 assigned to Moelnlycke A B; and WO 96/09165 assigned to Exxon. In this way, biological contaminates carried by liquids are prevented from passing through such fabrics. However, in some instances, surgical drapes formed from absorbent fabrics and/or liquid impervious films, while being liquid and airborne contaminate impervious, sacrifice other drape properties, such as meeting Class 1 flammability requirements per NFPA 702-1980, tear strength, being relatively "lint free" (not containing loose fibrous elements), and drape slippage. Class 1 flammability requirements are met when a material takes 20 seconds or greater for a flame from a standardized ignition source to spread 5 inches according to NFPA 702-1980 test conditions.
In some instances, surgical drapes fashioned from liquid absorbent fabrics alone, such as fabrics formed from hydrophilic fibers, sufficiently absorb liquids and are more breathable and thus more comfortable to the wearer than nonporous materials. However, these improvements in comfort and breathability provided by such nonwoven fabrics have generally occurred at the expense of barrier properties of the drape.
The need for improved liquid absorptivity and fluid impervious barrier properties has resulted in the introduction of hydrophilic fibers into various layers of surgical drapes. One commercially available drape, assigned to Moelnlycke AB, and sold under the tradename Klinidrape.RTM., comprises a liquid absorbent nonwoven top sheet containing inherently hydrophilic rayon staple (discontinuous) fibers, a fluid-impermeable intermediate sheet of polyethylene, and a bottom sheet of cellulose wadding. Although the Klinidrape.RTM. has liquid absorptivity and fluid impermeability, the drape produces relatively numerous lint particles and does not pass the Class 1 flammability requirements of NFPA 702-1980.
In order to improve drape strength without drastically increasing the drape density, spunbonded fabrics containing continuous synthetic filaments have been laminated with films and incorporated into surgical drapes. Such laminate fabrics are relatively low in cost. One such laminated fabric is a non-absorbing surgical drape, disclosed in GB 2296216, which is assigned to Kimberly-Clark Worldwide, and comprises a multilayer film bonded to a support layer, such as a hydrophobic spunbonded fabric layer. A similar laminate, disclosed in WO 96/09165 and assigned to Exxon, comprises a microporous film adhesively bonded between an outer nonwoven layer containing hydrophobic spunbonded filaments and a hydrophilic nonwoven inner layer. With respect to applications as surgical drapes, the film component provides a barrier to fluid, while the spunbonded component provides strength to the drape. However, since the spunbonded fabric component of the above laminates fail to exhibit hydrophilic properties, the drapes lack fluid absorbency.
One composite fabric, a spunlaced fabric/"dimpled" film laminate, disclosed in U.S. Pat. No. 5,546,960 to Billgren and assigned to Moelnlycke A B, consists of an absorbent fabric bonded to a film with applications targeted for use in surgical garments, such as gowns and drapes. The above laminate is described as possessing absorptivity and barrier properties with respect to fluids. The absorbent fabric is specified as a spunlaced nonwoven, which is different from the hydrophilic meltspun fabric of the present invention.
Another composite fabric, disclosed in U.S. Pat. No. 4,379,192 to Wahlquist et al., comprises an absorbent fabric bonded to an impervious film with applications targeted for use in surgical garments, such as gowns and drapes. The above laminate is described as possessing absorptivity and barrier properties with respect to liquids. The absorbent fabric is specified as a meltblown nonwoven, which may also contain a surface layer in the form of a continuous and randomly dispersed fiber layer.
None of the laminates disclosed above address the need to reduce the slippage that is prone to occur between the exposed surfaces of a drape or adjacent drapes.
Consequently, there exists a need in the art for surgical drapes and methods for making the same, which provide liquid absorptivity, liquid strike-through protection, drape strength and reduced drape slippage at a relatively low cost. Such improved materials and methods are provided by the present invention and will become more apparent upon further review of the following specification and claims.